Technical note: On the intercalibration of HIRS channel 12 brightness temperatures following the transition from HIRS 2 to HIRS 3/4 for ice saturation studies

Kurzfassung

For studies of trends in ice supersaturation in the upper troposphere we need very long time series of upper tropospheric humidity. The set of HIRS channel 12 satellite data can be used for this purpose, since Shi and Bates (2011) had provided an intercalibrated time series of channel 12 brightness temperatures. In the current paper we improve the intercalibration at the low tail of brightness temperatures, which leads to a more homogeneous time series of upper-tropospheric humidities.